It's 180,000 carats and weighs 840 pounds. Its value is estimated somewhere in the $370 million range, but really, the Bahia Emerald is so rare it's virtually priceless. No wonder the raw gem, which was found in 2001, is such a hot property — and has been at the center of a legal saga that's lasted years. »3/30/15 7:42pm Yesterday 7:42pm

Scientists, by definition, investigate the unknown. And where there's the unknown, there's danger. (There's also a lot of immense tedium and fiddling around with trivial details.) Sometimes, an apparently run-of-the-mill scientific expedition can turn deadly, without any warning. »7/25/12 10:00am 7/25/12 10:00am